RÉSUMÉ
Objeetive:To investigate the effect of Iranian honey,cinnamon and their combination against Streptococcus mutans bacteria.Methods:Nine experimental solutions were examined in this study,including two types of honey (pasteurized and sterilized),two types of cinnamon extract (dissolved in distilled water or dimethyl sulfoxide) and five different mixtures of cinnamon in honey (prepared by admixing 1％-5％ w/w of cinnamon extract into 99％-95％ w/w of honey,respectively).Meanwhile,each of mentioned agent was considered as the first solution while it was diluted into seven serially two-fold dilutions (from 1∶2 to 1∶128 v/v).Therefore,eight diffcrent concentrations of each agent were tested.The antibacterial tests were performed through blood agar well diffusion method,and the minimum inhibitory concentration (MIC) was determined.Ultimately,the data were subjected to statistical analysis incorporating Two-way ANOVA and Bonferroni post hoc tests (α =0.01).Results:The highest zone of inhibition was recorded for the mixtures of honey and cinnamon while all the subgroups containing 95％-99％ v/v of honey were in the same range (P ＜ 0.01).The MIC for both honey solutions were obtained as 500 mg/mL whereas it was 50 mg/mL for both cinnamon solutions.Moreover,the MIC related to all honey/cinnamon mixtures were 200 mg/mL.Conclusions:A profound synergistic effect of honey and cinnamon was observed against Streptococcus mutans while there was no significant difference among extracts containing 99％-95％ v/v of honey admixing with 1％-5％ v/v of cinnamon,respectively.
RÉSUMÉ
Background: Flexural strength (FS) is one of the most important properties of restorative dental materials which could be improved in fiber-reinforced composites (FRCs) by several methods including the incorporation of stronger reinforcing fibers. Aim: This study evaluates the influence of the glass fiber diameter on the FS and elastic modulus of FRCs at the same weight percentage. Materials and Methods: A mixture of 2,2-bis-[4-(methacryloxypropoxy)-phenyl]-propaneand triethyleneglycol dimethacrylate (60/40 by weight) was prepared as the matrix phase in which 0.5 wt. % camphorquinone and 0.5 wt. % N-N'-dimethylaminoethyl methacrylate were dissolved as photoinitiator system. Glass fibers with three different diameters (14, 19, and 26 μm) were impregnated with the matrix resin using a soft brush. The FRCs were inserted into a 2 × 2 × 25 mm 3 mold and cured using a light curing unit with an intensity of ca. 600 mW/cm 2 . The FS of the FRCs was measured in a three-point bending method. The elastic modulus was determined from the slope of the initial linear part of stress-strain curve. The fracture surface of the composites was observed using scanning electron microscopy to study the fiber-matrix interface. Statistical Analysis: The results were analyzed and compared using one-way ANOVA and Tukey's post-hoc test. Results: Although the FS increased as the diameter of fibers increased up to 19 μm (P < 0.05), no significant difference was observed between the composites containing fibers with diameters of 19 and 26 μm. Conclusion: The diameter of the fibers influences the mechanical properties of the FRCs.